Accounts Receivable (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of accounts receivable
Accounts receivable, principally trade	$ 133,847	$ 131,810
Less allowance for doubtful accounts	(6,711)	(1,198)
Accounts receivable, net	127,136	130,612
Marine seismic contractor [Member]
Summary of accounts receivable
Less allowance for doubtful accounts	$ (5,600)